Because his organization was riddled with felons, I suppose. The thinking is, "where there's flames, there's fire."
I've heard talk about it, but I don't think there's anyone in that bunch with the courage or intelligence to pull it off. And given the way Mattis regards that mess, I would say the military would not stand for it.
So are the weasels...
I notice that years of investigation by a partisan and hostile House committee and tens of millions of our tax dollars came up with exactly nothing. What do you think more of that would produce? At some point, one needs to come to terms with things as they are.
On the other hand, Mueller is regularly taking down felons. Maybe Trump is in his sights, maybe not. We'll learn soon enough. Be patient.
And be glad the rule of law still prevails.